Wildcard Syntax

Apache ActiveMQ Artemis uses a specific syntax for representing wildcards in security settings, address settings and when creating consumers.

The syntax is similar to that used by AMQP.

An Apache ActiveMQ Artemis wildcard expression contains words delimited by the character . (full stop).

The special characters # and * also have special meaning and can take the place of a word.

The character # means “match any sequence of zero or more words”.

The character * means “match a single word”.

So the wildcard news.europe.# would match news.europe, news.europe.sport, news.europe.politics, and news.europe.politics.regional but would not match news.usa, news.usa.sport or entertainment.

The wildcard news.* would match news.europe, but not news.europe.sport.

The wildcard news.*.sport would match news.europe.sport and also news.usa.sport, but not news.europe.politics.

Customizing the Syntax

It’s possible to further configure the syntax of the wildcard addresses using the broker configuration. For that, the <wildcard-addresses> configuration tag is used.

<wildcard-addresses>
   <routing-enabled>true</routing-enabled>
   <delimiter>.</delimiter>
   <any-words>#</any-words>
   <single-word>*</single-word>
</wildcard-addresses>

The example above shows the default configuration.